This invention relates to a dilator and an introducer having cooperating parts for releasably locking the dilator and introducer together with the dilator extending into the introducer and axially therethrough.
In the prior art it is known to provide dilator and introducer tubular portions with interference fits in an attempt to prevent the dilator from accidentally separating from the introducer and falling onto a surface whereby the dilator becomes contaminated and has to be thrown away. Further, it is known to provide an introducer with radially outwardly extending, diametric opposite tabs at its proximal end and a dilator having a hub portion that has diametric opposite, axially extending clip legs with leg axial mid-portion joined to the hub, axial inner hook ends for abutting against the axial inner (distal) surfaces of the tabs of the introducer and axial outer portion that when manually squeezed together (toward the hub), move the hook ends apart to permit axial separation of the dilator from the introducer. This results in the dilator hub end portion being somewhat more bulky than desired.
Additionally, problems are encountered when a dilator introducer combination extends within a living body, for example a subclavian vein, and only the dilator is removed. With presently known introducers, in order to prevent either the loss of blood from the human body or air being aspirated into the body, through the introducer, the doctor or another party places their thumb over the introducer proximal end.
In order to overcome problems such as described above and to provide an improved structural arrangement for releasably retaining a dilator and introducer in a coupled relationship, as well as achieving other advantages, this invention has been made.
A mechanical locking member is provided on the tab of an introducer to removably remain in an annular groove, or a radially recessed arcuate portion, of the hub of a dilator to lockingly retain the dilator to the introducer with the tubular member of the dilator extending into the tubular portion of the introducer. In one embodiment, the locking finger is resiliently retained in the groove while in another embodiment, a hub flange is rotatable relative to the introducer locking finger between a position permitting axial separation of the dilator from the introducer and a position blocking the axial separation of the dilator from the introducer. In a third embodiment, a slider is mounted on the introducer tab, the tab in turn mounting the locking finger for movement between a dilator introducer coupling position and a dilator introducer uncoupling position, the slider also serving to substantially eliminate egress flow through the introducer when the dilator has been removed from the introducer.
One of the objects of this invention is to provide a new and novel introducer and dilator combination that is releasably couplingly engageable for retaining the dilator tubular portion extending within the introducer tubular portion. Another object of the invention is to provide new and novel means on an introducer to lockingly couple to a conventional hub of a catheter or dilator to prevent accidental separation. An additional object of this invention is to provide an introducer having new and novel means for selectively blocking fluid flow through the introducer tubular member when the dilator has been axially separated from the introducer.